Need Help UCJV300-160 GHOSTING

[Kane]

HI Guys.

Quick question.. I am having ghosting, I have identified its due to the vinyl (lifting / bubbling) during printing. and it seems to happen near the middle of the machine. I have tried different media and PR settings and it still happens...

It only happens though on Vinyl.. not paper or PVC banner material or cling etc.. just Self Adhesive Vinyl.

The printer is in a room maintained to 22 degrees and so is the vinyl... I dont have any issues with my solvent machine (which has a heat bed)


So I can only come to the conclusion.. Vacuum pump faulty or something... or PR bias thats causing media screw...


Any thoughts will be welcome.

 

[White Haus]

Do you have pictures?

 

[Kane]

As you can see its not all of the media, so it cant be the calibration.. otherwise it would affect the entire sheet. I can clearly see the media bubble and lift where this ghosting is happeneing.

 

[Kane]

 

[balstestrat]

Vacuum not working?

 

[Kane]

Thats my assumption, but the vacuum does come on... but it ONLY affects the vinyl... no poster paper or anything else.

 

[White Haus]

Yeah we get that on our UCJV as well, it's very frustrating. Most of the time it only happens before the media is taped to the take up reel. You're "not supposed to", but I've manually turned some of the inside pinch rollers off a few times and sometimes that will help.

Usually only happens on cheaper materials with a certain type of liner, or banner stock. I guess they get affected more by the bulbs and buckle more.

 

[Kane]

I think I have identified the issue, Has anyone had an issue with the UV lights (curing the vinyl?) The vinyl after its come out the machine is so brittle almost as though its being cooked?

 

[joeks]

Following this as I have this problem as well. Vinyl lifting slightly, mostly in the center, causing small head strikes and the ghosting effect when printing bidirectional.

 

[Kane]

Right so far 3 people with the same machine on 3 different continents having the same issue?

If you guys could answer the following questions as I think I might have found whats causing mine...

1) What is the average temp you have where your machine and media is kept?

My machine is bent,, (my diagnoses) but the mimaki engineers and the company I bought the machine from are telling me media.. I think they know its fcked and they are just covering their tracks.. Ill be doing a lovely video soon, but machine looks bent, As you can see by the self levelling laser,, putting it square against the frame in multiple locations all say the same thing... its bent.

 

[joeks]

If your machine is bend, that mightbe a proper cause for the issue.
My machine is 3 months old, looks brand new and straight (i think).

There's a topic about "patchy printing" https://signs101.com/threads/mimaki-ucjv300-160-patchy-printing.162166/ which is an issue i also have. Could be caused by the lifting/bulging or the media. Have small headstrikes every day because of this. If I prefeed about 50cm-100cm and tape it to the roll it works ok most of the time (no headstrikes) but still can have the patchy printing bands and areas. I think it has something to do with the pinch rollers. Maybe their pressure is not 100% the same and causing a slight difference in feed?

Here are some photos of today. Black areas are supposed to be full black, no bands of gradients whatsover.

Oh, about ambient temperature, UCJV300-107 and media are in the same room which is a pretty contant 18-19 degrees celcius.

 

[Kane]

According to Mimaki, the machine needs a min of 20 degrees, As for my machine being bent.. I was having the same issue, I was getting patchy or bi directional "ghosting" happening due to the media rising off the platten. Both Mimaki and the company I bought it from say its temps, and have ignored and not even answered the fact that my machine is bent.. almost as though its impossible.. well when you put a laser level up against the frame in multiple locations and they are all showing the same thing.. its hard to ignore...

Your pictures look like you have issues with your banding, can clearly see lines going across the page...

whats your Drop Position settings? and banding? when last did you do a calibration?

 

[RonnyCrack]

I'm having the same issue, except oddly it only happens on higher scan speeds/lower resolutions. It's tough to tell if lower resolution itself causes ghosting, or if it's just lower resolution itself. 1200x1200 gets me near perfect results, except...

I'm also running into some banding, which is new unfortunately. Feed comp adjusted to no avail. Test prints yield no information, there's maybe one nozzle out at a time, but it shouldn't be causing this significant of banding at 1200x1200 resolution, or at least I wouldn't think so based on my use so far. Also most noticeable on greens and light blues. Has anyone figured anything out in the last year and a half?

 

[Ma_____]

The UCJV loses vacuum through the holes under the print plate. There is a procedure to reduce vacuum loss.

Remove print plate : 1) the holes through which the cables pass, etc. close with some tape. 2) Epto sealer place on the partition plate.

In print. 3) The vacuum holes where there is no medium close

 

[dariusaleksas]

We have the same thing with our brand new UCJV. I am getting this only with our Clear vinyl (Orafol, paper liner) and it gets so bad that I get media strikes here and there. I raised the head to the MIDDLE position, but it did not really help. I noticed that vinyl starts making 'waves' in the back before even hitting the print flat. I attribute this to our interior climate. It can get a bit hot and humid here. I always lower temp inside and make our AC cool down and dry our air before printing clear vinyl. It really helps us with this issue. I assume this specific paper liner absorbs too much damp air and bloats up creating waves. This was always negated by heat on our eco-solvent printer before. Just last week I adjusted vacuum power to MAX on our UCJV, and it looks like that helped with this problem too.

 

[Solventinkjet]

Make sure your pinch rollers are in the proper positions. They can drift over time and not be on the girt part of the grit roller. If you look at the rail the pinch roller slide on, there are 2 triangle. Make sure the pinch roller is between those triangles or you will get feed, skew, and vinyl bunching issues.